The NFC version of MiBand 6 supports bus cards in more than 200 cities, such as Beijing-Tianjin-Hebei Interconnection Card, Shanghai Bus Card, wuhan tong, Zhengzhou Greentown Pass, Jiangsu One Card and Jilin Pass. But if you are a Mac (ios 10.6 or above), there may not be so many cities opened. If your old version of mi band nfc is bound with a bus card, you can back up the existing bus card to the cloud first, and then bind the novice ring. Then open the card package function, select the backup bus card, and select Move in. After moving in, the card number, balance, transaction record and the accumulated amount of the subway in the current month remain unchanged.